It is well-known that the sound produced by a snoring person can be a great annoyance both to the snoring person as well as to a bed-partner of the snoring person. The snoring sound is characterized by periodic loud noise bursts with silent periods in between. Particularly, the partner of a snoring person is woken up many times during the night, by suchlike non-regular snoring sound. Partners wake up specifically when the noise level increases suddenly, but equally so when the snorting stops for a while.
An active noise reduction merely for reducing, using reference signal supply means, an error microphone and control speaker, the level of a noise source, such as an unsteady sound having a varying sound pressure level, an intermittent sound including silent portions and emitted by a sound source that intermittently stops, is disclosed by the document US 2007/076 896 A1, wherein an active noise reduction control apparatus is used to reduce a to-be-reduced noise emitted from the sound source by determining a reference signal in dependency of the noise and generating a control sound which is dephased relatively to the reference signal. An error microphone detects the synthesis of the sound pressure of the control sound and the to-be-reduced noise and if necessary updates filter coefficients of the filtering processing device of the active noise reduction control apparatus. Disadvantageously this active noise reduction control apparatus comprises a comparatively high computing power for processing the very complex and extensive algorithm for reducing the to-be-reduced noise.